Experimental Characterization of MFDC/CHC Resistance Spot Welding

Abstract

Resistance spot welding is widely used for joining sheet metal materials in the automotive industry. Most of the existing resistance spot welding systems are single-phase AC-based, and with constant current control. The medium frequency DC (MFDC) system with constant heat control (CHC) is new technology in the resistance spot welding industry. This system promises dramatic improvement on the spot weld quality. However, many of the CHC features are still not known and need to be explored. This paper presents an experimental study on a new MFDC/CHC spot welding system. The goal is to characterize the MFDC/CHC welding process in terms of the process parameters, including the target energy level, force, and welding time. Real time process signals such as force, current, and tip voltage were also collected and analyzed to compare with the traditional spot welding process.